This is still listed in doc/ToDo:

  * named arguments like foo(nation:="german") or foo(nation: "german").

Over a year ago, there was a popular RCR
[http://www.rubygarden.org/article.php?sid=217] which provided the
second syntax above by mandating a general shortcut to symbols used as
Hash keys.  This RCR has yet to be accepted/rejected.

Matz has looked into it and found it to be more difficult than expected.
[ruby-talk:19912].  I'm guessing he means fitting such syntax into the
current parser.

_why

David Heinemeier Hansson (david / loudthinking.com) wrote:
> 
> "Some languages feature ``keyword arguments''---that is, instead of 
> passing arguments in a given order and quantity, you pass the name of 
> the argument with its value, in any order.  Ruby 1.6 does not have 
> keyword arguments (although they are scheduled to be implemented in 
> Ruby 1.8)."
> 
> Since "New & Shiny" [1] didn't speak of it, I reckon it didn't make it. 
> So is this scheduled for a 1.8.x release, postponed to 2.0, or dropped 
> altogether?
>